A Physical cell ID (PCI) may be used for identifying an evolved node B (eNB)/small cell in a physical layer. Since in a LTE-A system, the PCI is closely related to mechanisms such as scrambling sequence generation, cell search and resource mapping, the PCI plays an important role in the physical layer.
The PCI is critical information for scrambling sequence generation in the physical channel, and plays a key role in reducing interferences in a control channel and a broadcast channel. Meanwhile, the PCI corresponds to a Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS) sequence, a Cell-specific Reference Signal (CRS), and the like, and is closely related to frequency offset values of the CRS and control channel resource mapping. Therefore, in order to avoid interferences between neighboring cells, and particularly to avoid interferences between intra frequency cells, it is required to reasonably allocate 504 PCIs.
In the conventional technology, in order to suitably allocate PCIs, a planning method is primarily adopted, where a fixed PCI is allocated to a cell when the cell is initially deployed, and manual configuration is required if the PCI needs to be changed. In a scenario of ultra-dense deployment of small cells, interferences between small cells are more severe. Therefore, the method in the conventional technology may cause a high maintenance cost and a great burden on cell planning and lacks flexibility, thus it is difficult for the method to be adapted to automatic configuration mechanisms such as a plug-and-play mechanism, and to meet requirements of an unplanned small cell deployment scenario which is even more flexible.